Coral Disease Outbreak – Turks & Caicos Islands

January 2019 : South Caicos

Dying corals were first observed in the Admiral Cockburn Land and Sea Park in January 2019 by staff at the School for Field Studies (SFS). By March it was realized that stony coral tissue loss disease (SCTLD) was responsible for this unusual mortality. Initial assessments of the damage, that began in April 2019 (when up to 24 species were reported affected) with visual belt transects and roving photo surveys, were continued in June and October. Several affected corals were videographed at different times in April to create digital 3-D models of their surfaces to determine the rates at which the disease was spreading.

Sixty healthy corals (at 10, 20 and 30 m) were tagged in October and will be inspected for signs of infection in November. Visual transect surveys and digital 3-D modeling of newly diseased corals will be repeated at this time. On South Caicos, Agaricia agaricites and Dichocoenia stokesii are the most common of the species that are susceptible to SCTLD, although a higher percentage of Orbicella faveolata are affected by the disease.

Corals
of species susceptible to SCTLD were becoming sick at Spanish Anchor near the
southwestern tip of the island on April 17, and an outbreak of SCTLD was
apparent here by May 23 (A. Zimmermann, pers. comm.). By mid-August, the
disease had spread north (downcurrent) to NW Point and Grace Bay on northern
coast of Providenciales. Roving diver surveys are being used to follow the
progression of SCTLD by the staff at the Turks and Caicos Reef Fund (TCRF) and
Department of Environment and Coastal Resources (DECR) at three westerly
oriented sites (two off West Caicos, one to its north in Sandbore Channel) and
two that are northerly oriented (one each off Providenciales and Pine Cay). Thirty
corals (or coral groups) have also been marked for ongoing photo monitoring of
their health at each of the two northern sites.

Educational outreach about SCTLD and how to minimize its spread has been given to dive and snorkel boat operators by TCRF staff in Providenciales and to dive shops by DECR staff in Grand Turk. Members of the Hotel and Tourism Association have been informed, and are contributing funding to support the TCRF/DECR disease monitoring effort.

With
contributions for South Caicos from Drs. Heidi Heitler and Franziska Elmer (School
for Field Studies), and for West Caicos–Providenciales and Pine Cay from Alizee
Zimmermann (Turks and Caicos Reef Fund).